The present invention relates to a linear motor having reduced force ripple.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
Permanent-magnet linear motors generally have a certain amount of force ripple. This disturbing force ripple is caused, inter alia, by the reluctance forces between the permanent magnets and the teeth of the primary part, as well as the interaction between the secondary and primary magnetic fields in the air gap. However, it is desirable for linear motors, and in particular also cylindrical linear motors to produce the same forces with the same current in the permissible axial movement range. Only when scarcely any force fluctuations occur over the movement range with the same current, is the force ripple appropriately low.
It would be desirable and advantageous to address this problem and to obviate other prior art shortcomings by reducing the force ripple.